In this section we discuss how much the HHL algorithm utilizes the entanglement efficiently as we discussed previously in the Grover's algorithm.
In this reason we will compute the entanglement at each stage of the HHL algorithm. For simplicity, we will consider only the case of Eq. (REF ).
Thus, the three-tangle[1]} and \(\pi \) -tangle[2]} will be computed explicitly after taking a partial trace over the ancilla qubit in Eqs. (REF ), (REF ), and (REF ).
